1. Field
Apparatuses consistent with exemplary embodiments relate to electromagnetic wave reflectors and optical devices including the same.
2. Description of Related Art
The miniaturization and related integration of optical structures and optical systems make it possible to develop products with new functions and to diversify the structure of many products. In this regard, research and development have been actively conducted into implementing super-mini thin-film mirrors, lenses, spectroscopes, and other optical devices. A thin-film mirror (that is, a thin-film type reflector) may have a distributed Bragg reflector (DBR) structure or a high-contrast grating (HCG) structure.
A DBR structure includes several tens of dielectric layers which each satisfy a thickness condition of λ/4 (where λ indicates a wavelength of light). Accordingly, a DBR structure has a relatively large thickness of at least several micrometers (e.g., 5 μm or more) and requires a long processing time, and a large amount of material is required for manufacturing the structure. An HCG structure includes a subwavelength grating (SWG), and an ultra-fine grating in the form of a perfect rectangular parallelepiped is not easy to manufacture. Therefore, a reflector is needed which is easy to manufacture while having a small thickness and also excellent reflection efficiency. Such a reflector could be usefully applied to any of various optical devices.